'Contact' Collection

Contact is an incredibly popular topic area widely used in civil and mechanical engineering fields. NAFEMS has specially selected the following publications to provide the perfect overview of contact and how to undertake its analysis:

Linear finite element analysis has for many years been widely used in the civil and mechanicals engineering fields and, in particular,in the construction, automotive, aerospace, and offshore sectors. Finite element analysis is an integral part of the design cycle in many companies.

Finite element programs that have the capability to solve non-linear problems have also been available for many years but often have been considered for use only in specialised industries such as nuclear engineering and advanced gas turbine research. In fact, the application of non-linear finite element analysis to general engineering has been growing rapidly, using commercially available packages of high quality and reliability. This book deals specifically with the subset of non-linear problems involving contact or friction.

In this book the aim is to give sufficient background to the terminology and techniques specific to contact and friction analysis. In addition typical problems areas, which may arise, are highlighted and guidance as to how they can be resolved is provided. A number of examples are used throughout the text to illustrate the concepts and potential applications.

In this book we aim to provide some background information about the principles of the finite element technique as applied to nonlinear problems. The benefits of using nonlinear finite element analysis are highlighted, and some general guidelines are given for efficient use of the technique.

The book is aimed at decision-makers; those practising engineers and managers who may influence the design process within their organization. The objective of the booklet is to demonstrate to the engineers,in a clear and practical manner, he reasons why their organizations should be using nonlinear Finite Element analysis.

The decision to use any tool or process should be driven by commercial factors. A company should consider the use of any available tools that may reduce its development costs, reduce its lead times, and enable it to develop products that are better than those produced by its competitors, or enable it to manufacture products using less material and less complex or costly processes.

In many cases the use of nonlinear finite element analysis can provide these kinds of benefits. It is perhaps appropriate, therefore, that engineers should consider whether they can afford not to use nonlinear FEA.

There are, of course, some negative aspects to this issue: any prospective user of nonlinear finite elements should consider the additional costs of the software and the computer on which to run it, the costs associated with training staff, and the additional work required to generate the material and structural data that a good analysis demands. In this booklet we endeavour to provide a balanced view of the benefits and costs of using nonlinear FEA.

NAFEMS has published a survey on Finite Element Analysis of contact and friction and a booklet on how to undertake contact and friction analysis. A contact benchmarks report on two-dimensional problems was published as a step in establishing a set of FE Contact benchmarks. It was acknowledged that although the current published NAFEMS benchmarks were limited in scope, they were important as the first step in establishing contact benchmarks.

Further Finite Element analyses were performed to establish the geometric parameters, material constants, values of the applied loads and the coefficient of friction.

The current report presents the results of the Finite Element Analyses performed on 2D and 3D approximations of the proposed problems. Since all proposed benchmarks can be reasonably well approximated with 2D or an axisymmetric solution, all target results presented here have been obtained with 2D or an axisymmetric Finite Element analysis. In addition, 3D analyses have been performed and the results have been compared with the initial 2D solutions (with the exception of Contact Benchmark 1).

Frequently, reports on results of benchmark analyses present numerical solutions for selected problems, generated by different users using different Finite Element codes. Often the selection of different numerical input parameters by the analyst is not presented in the report and the analyst presents his“best choice” of the generated solutions for a particular problem.

As a result the effect of specific parameters, such as applied mesh density, element type, contact parameter settings, number of loading steps etc. is difficult to quantify and it is not clear whether obtained differences are caused by differences in the applied Finite Element code or differences in user input. The results presented in this report not only compare results of different Finite Element codes using as closely as possible identical input parameters, but also show the effect of variations in these parameters.